1. Field
Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to supporting Multimedia Broadcast/Multicast Service (MBMS) in a new carrier type, such as an extension carrier, in LTE.
2. Background
Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, etc. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Examples of such multiple-access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (OFDMA) networks, and Single-Carrier FDMA (SC-FDMA) networks.
A wireless communication network may include a number of base stations that can support communication for a number of user equipments (UEs). A UE may communicate with a base station via the downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station. In an example, a base station can assign a number of downlink and/or uplink resources to a UE. Moreover, the base station can allow the UE to establish multiple carriers for communicating with the base station over the downlink or uplink using multiple physical or virtual antennas or other radio resources to improve communication throughput.
In some systems, the base station may provide multi-media service and a unicast service to UEs. For instance, such as service includes Multimedia Broadcast/Multicast Service (MBMS). In MBMS, a plurality of subframes, e.g. Multicast/Broadcast over Single Frequency Network (MBSFN) subframes, of a radio frame may be allocated to support broadcast and/or unicast service. Further, the radio frame may be part of a set of radio frames that repeats over a transmission interval to deliver the service. In current implementations of MBMS, the MBSFN subframes can be configured with a non-MBMS region for providing control information, and an MBMS region for carrying data traffic. In particular, in current implementations, the non-MBMS region of a subframe may include the first several OFDM symbols, and thus the MBMS region is defined as the OFDM symbols not used for the non-MBMS region.
Problematically, however, a new carrier type, defined in LTE Release 12 (Rel-12) and also referred to as an extension carrier, may contain an enhanced control channel spanning at least the MBMS region (and possibly also spanning the non-MBMS region, if there is no legacy non-MBMS region), e.g. the data traffic region, of a MBSFN subframe.
Accordingly, mechanisms for supporting broadcast and unicast services are desired for an LTE new carrier type.